Lamictal and difficulty breathing

I have been on Lamictal for approximately 7 years. The product initially seemed to work a bit on controlling my seizure activity, and did provide a bit more confidence in social situations. At this point I was taking 400mg per day, and had little side effects other than the absent mindedness, and occasional problems with vertigo.
Briefly, about a year ago, I began having an increasing number of partial and general seizures, and was brought up to a dosage of 700mg per day. It was at this point that I began noticing what could only be called "hard-core" side effects. These included days where I was just totally confused, paranoid, suicidal, having an unrelenting feeling of not being able to breath, feeling bloated in my abdomen, and regularly being struck with a very irregular, very scary, rapid heart beat.
At this point, I am taking 600mg per day, and am still having most of these side-effects, but in decreased frequency. My neurologist never mentioned any of these possible symptoms, and doesn't seem overly concerned about any of the problems that I have mentioned in the past. With this in mind, it is somewhat relieving to see that there are others out there who are noticing similar effects.
If anyone can explain the difficulty breathing thing a bit more, it might help me wrap my brain (no pun intended) around this whole mess. I'm not sure if it's related to a decrease in blood pressure - I've been monitoring mine and haven't seen any irregularities. Or if it's related to a decrease in the amount of oxygen in the circulatory system due to the drug itself, or as a side-effect of the shallow breathing I have read about in other posts here.

I'm having serious side effects currently. The onset of the side effects began after taking Lamictal for over 2 months. I started slowly on 25 mg and gradually increased to 200. I felt a great improvement in Bipolar disorder-mood swings- at 100mg but was told that is not the theraputic dose, so we increased to 200mg.

I had no side effects until the rash began to appear. At first only on legs, then arms, then neck, then face...and surprisingly in private areas. Unbearable itching. Rash continued to rage even after a pack of steroids. Swelling became apparrent in face and entire body. Slight difficulty breathing. Went to the ER and received another dose of steroids intravenously. The rash continues to improve but is still extremely itch. The swelling improved for a couple of days but is back. Had one day of severe headache. It has been 14 days and today I am experiencing blurred vision in the left eye, and new swelling in the tongue.
I sit at home with an Epi Pen next to me waiting to hear back from the doctor.

All of this is so unfortunate because I felt more stable than I have in years while on the medication. I'm feeling very concerned about my continuing side effects. Don't know what to expect.

I began Lamictal in Jan 07. About a week after I began it I noticed excess production of phlegm. I mean crazy phlegm production to the point I needed to spit every few minutes. I also noticed that I began to have difficulty breathing at times. I had no rash.
In February I developed a fever, chills, shortness of breath, severe fatigue and severe leg cramping in both legs. I thought I was having a heart attack it was so bad. I went off the drug and the symptoms subsided however now I am severely fatigued at times and my breathing is still not quite the same as it was prior to the medication.